1. Field of the Invention
The invention pertains to tubular conduit assemblies such as pipelines. While the invention may be applied to pipelines for various different uses, it is particularly well adapted for use in pipelines for conveying crude oil and similar substances having abrasive solids suspended or entrained therein.
2. Description of the Prior Art
The presence of solid particles in hydrocarbon liquids being conveyed by pipelines may cause severe wear problems due to abrasion of the interior of the pipelines. Regardless of the nature of the solids, the abrasion is particularly acute in the elbows or curved portions of the pipelines. Due to the inertia of the flowing material, the particles tend to strike the inner surface of the elbow rather than merely flowing parallel thereto, and the problem may be further compounded by turbulence in the elbows. Similar problems may occur in rectilinear conduit sections as well, e.g. where there is, for any reason, some degree of turbulence.
In the past, straight sections of pipe or other conduits have been lined with substances intended to protect the interior of the pipe sections from chemical or physical deterioration. However, as mentioned above, the straight portions of a pipeline do not typically represent the sites of the most severe physical abrasion problems. Furthermore, such sections represent the major portions of the pipelines as a whole, and coating or lining of such a large extent of pipeline is sometimes too expensive to be justified by the advantages obtained. In any event where pipelines or sections thereof have been coated or lined, the form of the lining and its engagement with the pipe bodies has not been entirely satisfactory for a number of reasons. Furthermore, the types of lining materials previously used have not been appropriate for high pressure environments and, in some instances, have been less than completely satisfactory in preventing wear because of chemical deterioration caused by the hydrocarbon liquids in the stream.